The Trophy 1802 (and most other boats) come from the factory without any sort of locking mechanism on the fuel cap. This not only may lead to fuel theft, but also the possibility of someone tampering with your fuel system (and it could be too late once you suspect something if the motor has already ingested the contaminated fuel).
Fortunately, Perko has developped a locking mechanism that fits into most Perko fuel caps. This one fit perfect on my Trophy 1802.
If you want to get additional information, or want to confirm if this will fit your boat, here is the link to Perko:
